In recent years, there have been diligently developed techniques for reducing power consumption of liquid crystal display devices. Reduction of power consumption is particularly important for liquid crystal display devices provided in portable devices such as mobile phones, smartphones, and laptop personal computers.
As a technique for reducing power consumption, there is known interlace driving in which a plurality of frames form a single screen by reducing the number of scanning lines included in a display section and carrying out scanning (selecting) every other scanning line or every two or more scanning lines.
Patent Literature 1 discloses a technique in which interlace driving and non-interlace driving are switched depending on which image, a moving image or a still image, is displayed as a display image, and a single screen is formed by (j+1)th frames in total by carrying out the interlace driving in such a way that scanning are carried out every j scanning lines in order of the k-th scanning line, the (k+(j+1))th scanning line, the (k+2(j+1))th scanning line, . . . , in the i-th frame, and scanning are carried out every j scanning lines in order of the k+1th scanning line, the (k+1+(j+1))th scanning line, the (k+1+2(j+1))th scanning line, . . . , in the (i+1)th frame.
FIG. 28 is a timing chart of a flat display device disclosed in Patent Literature 1 which carries out scanning every other scanning line (j=1) and two frames in total form a single screen.
In the interlace driving, as illustrated in FIG. 28, first, (odd-number)th scanning lines (for example, the first line, the third line, and then the fifth line) are scanned in the i-th frame. Next, (even-number)th scanning lines (for example, the second line, the fourth line, and then the sixth line) are scanned in the (i+1)th frame. By carrying out such scanning in the i-th frame and in the (i+1)th frame, all scanning lines are scanned and a single image is formed.
As described above, by reducing the number of scanning lines and scanning the scanning lines thus reduced, the interlace driving can reduce power consumption.